Lethal and sublethal effects of the emerging contaminant oxytetracycline on the embryo-larval development of Rhinella arenarum.

The antibiotic oxytetracycline (OTC) is commonly used in animal production and can enter aquatic ecosystems, causing adverse effects on non-target species. The aim of this work was to evaluate the lethal and sublethal effects of OTC on the embryonic and larval period of Rhinella arenarum, through standardized bioassays and oxidative stress (catalase-CAT-, superoxide dismutase-SOD-, glutathione S-transferase-GST-, reduced glutathione-GSH- and lipid peroxidation-TBARS-), neurotoxicity (acetylcholinesterase-AChE- and butyrylcholinesterase-BChE-) and genotoxicity (micronuclei test) biomarkers. Mortality was time and stage dependent, being the embryos (504 h-LC50 = 64.

Development and Diagnostic Accuracy of a Breath Test for Pancreatic Exocrine Insufficiency in Chronic Pancreatitis.

Objective: To develop a ¹³C-labeled substrate breath test by defining the optimal ¹³C-labeled substrate, substrate dose, test meal, and duration of the test and evaluating its accuracy for the diagnosis of pancreatic exocrine insufficiency (PEI) in chronic pancreatitis (CP).

Methods: Five consecutive prospective comparative studies in patients with known advanced CP and healthy controls were performed to develop the optimal breath test. Coefficient of fat absorption was used as the reference method.

Further solid-phase microextraction-gas chromatography-mass spectrometry applications: "on-fibre" and aqueous photodegradation of nitro musks.

Photodegradation kinetics of four nitro musks (musk xylene, musk tibetene, musk ketone and musk moskene) in solid-phase microextraction (SPME) fibres ("photo-SPME") and in an aqueous system were studied by means of gas chromatography-mass spectrometry (MS) detection. Musks fragrances were extracted from aqueous solutions using SPME fibres that subsequently were exposed to different UV irradiation times, generating photoproducts easily characterized by their mass spectra. Aqueous photodegradation studies followed by SPME were also performed and compared to photo-SPME.

Study of the photoinduced degradation of polycyclic musk compounds by solid-phase microextraction and gas chromatography/mass spectrometry.

Polycyclic musks are widely used synthetic fragrances that have been identified during the last few years in biota samples and environmental matrices. Nevertheless, there is a lack of information concerning the photodegradation behavior of these compounds. In this work, the photoinduced degradation of six polycyclic musk compounds (Cashmeran, Celestolide, Phantolide, Galaxolide, Traseolide and Tonalide) was studied using a solid-phase microextraction (SPME) fiber as support.

[Aortic debris in cerebrovascular ischemic disease].

Background: The aortic atherosclerotic debris is considered a high risk embolic source, being an independent predictor for cerebrovascular ischemia. The incidence is higher in the elderly and in patients with coronary artery disease. Transesophageal echocardiogram (TEE) is an important diagnostic tool that allows its detection.

Rapid determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin in water samples by using solid-phase microextraction followed by gas chromatography with tandem mass spectrometry.

A rapid and simple method of using solid-phase microextraction was developed for determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) in water samples. In this method, the target analyte is extracted from the sample into the polymeric coating of the fused-silica fiber. After exposure, the fiber is thermally desorbed in the heated injection port of the gas chromatograph, and a chromatographic analysis is performed by using low-resolution tandem mass spectrometry.

[Ischemic stroke: transesophageal echocardiographic findings].

Introduction: Since its initial application in 1976, the transesophageal echocardiogram (TEE) has improved the detection of cardiovascular emboligenic sources. Even though its indication in patients with stroke is still controversial, its use has contributed to the identification of potential embolic stroke sources.

Objective: To describe the transesophageal echocardiographic findings in ischemic stroke patients.

On-fiber photodegradation after solid-phase microextraction of p,p'-DDT and two of its major photoproducts, p,p'-DDE and p,p'-DDD.

The potential of performing photochemical studies in solid phase microextraction (SPME) fibers, "photo-SPME", to study the photodegradation of p,p'-DDT and two of its major degradation products, p,p'-DDE and p,p'-DDD, is shown. Analyses were carried out by gas chromatography mass spectroscopy detection. DDT was extracted from aqueous solutions using five different commercial coatings.

Optimization of a derivatization-solid-phase microextraction method for the analysis of thirty phenolic pollutants in water samples.

Solid-phase microextraction (SPME) coupled to gas chromatography-mass spectrometry has been applied to the extraction of 30 phenol derivatives from water samples. Analytes were in situ acetylated and headspace solid-phase microextraction was performed. Different parameters affecting extraction efficiency were studied.